Presently, more and more products are being dispensed as foam because the consuming public typically prefers foam products over their liquid predecessors. For example, foam soap, wherein a liquid soap is mixed with air to create a foam soap product, is quickly becoming more popular than the non-foam soap product that is simply dispensed as a liquid soap. In light of this, many different foam pumps have been designed and are now offered in the marketplace. Those of ordinary skill in the art will appreciate that the standard liquid pumps have been significantly redesigned to incorporate the air pumps necessary for advancing air to mix air with the liquid and create a foam. It is believed that the art would therefore benefit from the provision of a foam pump wherein the air pump mechanisms are simply added onto a common stock reciprocating piston liquid pump to provide a foam pump without any significant alteration of the liquid pump.